// Copyright (c) 2009-present The Bitcoin Core developers

// Distributed under the MIT software license, see the accompanying

// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include <core_io.h>

#include <addresstype.h>

#include <coins.h>

#include <consensus/amount.h>

#include <consensus/consensus.h>

#include <consensus/validation.h>

#include <crypto/hex_base.h>

#include <key_io.h>

#include <prevector.h>

#include <primitives/block.h>

#include <primitives/transaction.h>

#include <script/descriptor.h>

#include <script/interpreter.h>

#include <script/script.h>

#include <script/signingprovider.h>

#include <script/solver.h>

#include <serialize.h>

#include <streams.h>

#include <tinyformat.h>

#include <uint256.h>

#include <undo.h>

#include <univalue.h>

#include <util/check.h>

#include <util/result.h>

#include <util/strencodings.h>

#include <util/string.h>

#include <util/translation.h>

#include <algorithm>

#include <compare>

#include <cstdint>

#include <exception>

#include <functional>

#include <map>

#include <memory>

#include <optional>

#include <span>

#include <stdexcept>

#include <string>

#include <utility>

#include <vector>

using util::SplitString;

namespace {

class OpCodeParser

{

private:

    std::map<std::string, opcodetype> mapOpNames;

public:

    OpCodeParser()

    {

        for (unsigned int op = 0; op <= MAX_OPCODE; ++op) {

            // Allow OP_RESERVED to get into mapOpNames

            if (op < OP_NOP && op != OP_RESERVED) {

                continue;

            }

            std::string strName = GetOpName(static_cast<opcodetype>(op));

            if (strName == "OP_UNKNOWN") {

                continue;

            }

            mapOpNames[strName] = static_cast<opcodetype>(op);

            // Convenience: OP_ADD and just ADD are both recognized:

            if (strName.starts_with("OP_")) {

                mapOpNames[strName.substr(3)] = static_cast<opcodetype>(op);

            }

        }

    }

    opcodetype Parse(const std::string& s) const

    {

        auto it = mapOpNames.find(s);

        if (it == mapOpNames.end()) throw std::runtime_error("script parse error: unknown opcode");

        return it->second;

    }

};

opcodetype ParseOpCode(const std::string& s)

{

    static const OpCodeParser ocp;

    return ocp.Parse(s);

}

} // namespace

CScript ParseScript(const std::string& s)

{

    CScript result;

    std::vector<std::string> words = SplitString(s, " \t\n");

    for (const std::string& w : words) {

        if (w.empty()) {

            // Empty string, ignore. (SplitString doesn't combine multiple separators)

        } else if (std::all_of(w.begin(), w.end(), ::IsDigit) ||

                   (w.front() == '-' && w.size() > 1 && std::all_of(w.begin() + 1, w.end(), ::IsDigit)))

        {

            // Number

            const auto num{ToIntegral<int64_t>(w)};

            // limit the range of numbers ParseScript accepts in decimal

            // since numbers outside -0xFFFFFFFF...0xFFFFFFFF are illegal in scripts

            if (!num.has_value() || num > int64_t{0xffffffff} || num < -1 * int64_t{0xffffffff}) {

                throw std::runtime_error("script parse error: decimal numeric value only allowed in the "

                                         "range -0xFFFFFFFF...0xFFFFFFFF");

            }

            result << num.value();

        } else if (w.starts_with("0x") && w.size() > 2 && IsHex(std::string(w.begin() + 2, w.end()))) {

            // Raw hex data, inserted NOT pushed onto stack:

            std::vector<unsigned char> raw = ParseHex(std::string(w.begin() + 2, w.end()));

            result.insert(result.end(), raw.begin(), raw.end());

        } else if (w.size() >= 2 && w.front() == '\'' && w.back() == '\'') {

            // Single-quoted string, pushed as data. NOTE: this is poor-man's

            // parsing, spaces/tabs/newlines in single-quoted strings won't work.

            std::vector<unsigned char> value(w.begin() + 1, w.end() - 1);

            result << value;

        } else {

            // opcode, e.g. OP_ADD or ADD:

            result << ParseOpCode(w);

        }

    }

    return result;

}

/// Check that all of the input and output scripts of a transaction contain valid opcodes

static bool CheckTxScriptsSanity(const CMutableTransaction& tx)

{

    // Check input scripts for non-coinbase txs

    if (!CTransaction(tx).IsCoinBase()) {

        for (unsigned int i = 0; i < tx.vin.size(); i++) {

            if (!tx.vin[i].scriptSig.HasValidOps() || tx.vin[i].scriptSig.size() > MAX_SCRIPT_SIZE) {

                return false;

            }

        }

    }

    // Check output scripts

    for (unsigned int i = 0; i < tx.vout.size(); i++) {

        if (!tx.vout[i].scriptPubKey.HasValidOps() || tx.vout[i].scriptPubKey.size() > MAX_SCRIPT_SIZE) {

            return false;

        }

    }

    return true;

}

static bool DecodeTx(CMutableTransaction& tx, const std::vector<unsigned char>& tx_data, bool try_no_witness, bool try_witness)

{

    // General strategy:

    // - Decode both with extended serialization (which interprets the 0x0001 tag as a marker for

    //   the presence of witnesses) and with legacy serialization (which interprets the tag as a

    //   0-input 1-output incomplete transaction).

    //   - Restricted by try_no_witness (which disables legacy if false) and try_witness (which

    //     disables extended if false).

    //   - Ignore serializations that do not fully consume the hex string.

    // - If neither succeeds, fail.

    // - If only one succeeds, return that one.

    // - If both decode attempts succeed:

    //   - If only one passes the CheckTxScriptsSanity check, return that one.

    //   - If neither or both pass CheckTxScriptsSanity, return the extended one.

    CMutableTransaction tx_extended, tx_legacy;

    bool ok_extended = false, ok_legacy = false;

    // Try decoding with extended serialization support, and remember if the result successfully

    // consumes the entire input.

    if (try_witness) {

        SpanReader ssData{tx_data};

        try {

            ssData >> TX_WITH_WITNESS(tx_extended);

            if (ssData.empty()) ok_extended = true;

        } catch (const std::exception&) {

            // Fall through.

        }

    }

    // Optimization: if extended decoding succeeded and the result passes CheckTxScriptsSanity,

    // don't bother decoding the other way.

    if (ok_extended && CheckTxScriptsSanity(tx_extended)) {

        tx = std::move(tx_extended);

        return true;

    }

    // Try decoding with legacy serialization, and remember if the result successfully consumes the entire input.

    if (try_no_witness) {

        SpanReader ssData{tx_data};

        try {

            ssData >> TX_NO_WITNESS(tx_legacy);

            if (ssData.empty()) ok_legacy = true;

        } catch (const std::exception&) {

            // Fall through.

        }

    }

    // If legacy decoding succeeded and passes CheckTxScriptsSanity, that's our answer, as we know

    // at this point that extended decoding either failed or doesn't pass the sanity check.

    if (ok_legacy && CheckTxScriptsSanity(tx_legacy)) {

        tx = std::move(tx_legacy);

        return true;

    }

    // If extended decoding succeeded, and neither decoding passes sanity, return the extended one.

    if (ok_extended) {

        tx = std::move(tx_extended);

        return true;

    }

    // If legacy decoding succeeded and extended didn't, return the legacy one.

    if (ok_legacy) {

        tx = std::move(tx_legacy);

        return true;

    }

    // If none succeeded, we failed.

    return false;

}

bool DecodeHexTx(CMutableTransaction& tx, const std::string& hex_tx, bool try_no_witness, bool try_witness)

{

    if (!IsHex(hex_tx)) {

        return false;

    }

    std::vector<unsigned char> txData(ParseHex(hex_tx));

    return DecodeTx(tx, txData, try_no_witness, try_witness);

}

bool DecodeHexBlockHeader(CBlockHeader& header, const std::string& hex_header)

{

    if (!IsHex(hex_header)) return false;

    const std::vector<unsigned char> header_data{ParseHex(hex_header)};

    try {

        SpanReader{header_data} >> header;

    } catch (const std::exception&) {

        return false;

    }

    return true;

}

bool DecodeHexBlk(CBlock& block, const std::string& strHexBlk)

{

    if (!IsHex(strHexBlk))

        return false;

    std::vector<unsigned char> blockData(ParseHex(strHexBlk));

    try {

        SpanReader{blockData} >> TX_WITH_WITNESS(block);

    }

    catch (const std::exception&) {

        return false;

    }

    return true;

}

util::Result<int> SighashFromStr(const std::string& sighash)

{

    static const std::map<std::string, int> map_sighash_values = {

        {std::string("DEFAULT"), int(SIGHASH_DEFAULT)},

        {std::string("ALL"), int(SIGHASH_ALL)},

        {std::string("ALL|ANYONECANPAY"), int(SIGHASH_ALL|SIGHASH_ANYONECANPAY)},

        {std::string("NONE"), int(SIGHASH_NONE)},

        {std::string("NONE|ANYONECANPAY"), int(SIGHASH_NONE|SIGHASH_ANYONECANPAY)},

        {std::string("SINGLE"), int(SIGHASH_SINGLE)},

        {std::string("SINGLE|ANYONECANPAY"), int(SIGHASH_SINGLE|SIGHASH_ANYONECANPAY)},

    };

    const auto& it = map_sighash_values.find(sighash);

    if (it != map_sighash_values.end()) {

        return it->second;

    } else {

        return util::Error{Untranslated("'" + sighash + "' is not a valid sighash parameter.")};

    }

}

UniValue ValueFromAmount(const CAmount amount)

{

    static_assert(COIN > 1);

    int64_t quotient = amount / COIN;

    int64_t remainder = amount % COIN;

    if (amount < 0) {

        quotient = -quotient;

        remainder = -remainder;

    }

    return UniValue(UniValue::VNUM,

            strprintf("%s%d.%08d", amount < 0 ? "-" : "", quotient, remainder));

}

std::string FormatScript(const CScript& script)

{

    std::string ret;

    CScript::const_iterator it = script.begin();

    opcodetype op;

    while (it != script.end()) {

        CScript::const_iterator it2 = it;

        std::vector<unsigned char> vch;

        if (script.GetOp(it, op, vch)) {

            if (op == OP_0) {

                ret += "0 ";

                continue;

            } else if ((op >= OP_1 && op <= OP_16) || op == OP_1NEGATE) {

                ret += strprintf("%i ", op - OP_1NEGATE - 1);

                continue;

            } else if (op >= OP_NOP && op <= OP_NOP10) {

                std::string str(GetOpName(op));

                if (str.substr(0, 3) == std::string("OP_")) {

                    ret += str.substr(3, std::string::npos) + " ";

                    continue;

                }

            }

            if (vch.size() > 0) {

                ret += strprintf("0x%x 0x%x ", HexStr(std::vector<uint8_t>(it2, it - vch.size())),

                                               HexStr(std::vector<uint8_t>(it - vch.size(), it)));

            } else {

                ret += strprintf("0x%x ", HexStr(std::vector<uint8_t>(it2, it)));

            }

            continue;

        }

        ret += strprintf("0x%x ", HexStr(std::vector<uint8_t>(it2, script.end())));

        break;

    }

    return ret.substr(0, ret.empty() ? ret.npos : ret.size() - 1);

}

const std::map<unsigned char, std::string> mapSigHashTypes = {

    {static_cast<unsigned char>(SIGHASH_ALL), std::string("ALL")},

    {static_cast<unsigned char>(SIGHASH_ALL|SIGHASH_ANYONECANPAY), std::string("ALL|ANYONECANPAY")},

    {static_cast<unsigned char>(SIGHASH_NONE), std::string("NONE")},

    {static_cast<unsigned char>(SIGHASH_NONE|SIGHASH_ANYONECANPAY), std::string("NONE|ANYONECANPAY")},

    {static_cast<unsigned char>(SIGHASH_SINGLE), std::string("SINGLE")},

    {static_cast<unsigned char>(SIGHASH_SINGLE|SIGHASH_ANYONECANPAY), std::string("SINGLE|ANYONECANPAY")},

};

std::string SighashToStr(unsigned char sighash_type)

{

    const auto& it = mapSigHashTypes.find(sighash_type);

    if (it == mapSigHashTypes.end()) return "";

    return it->second;

}

/**

 * Create the assembly string representation of a CScript object.

 * @param[in] script    CScript object to convert into the asm string representation.

 * @param[in] fAttemptSighashDecode    Whether to attempt to decode sighash types on data within the script that matches the format

 *                                     of a signature. Only pass true for scripts you believe could contain signatures. For example,

 *                                     pass false, or omit the this argument (defaults to false), for scriptPubKeys.

 */

std::string ScriptToAsmStr(const CScript& script, const bool fAttemptSighashDecode)

{

    std::string str;

    opcodetype opcode;

    std::vector<unsigned char> vch;

    CScript::const_iterator pc = script.begin();

    while (pc < script.end()) {

        if (!str.empty()) {

            str += " ";

        }

        if (!script.GetOp(pc, opcode, vch)) {

            str += "[error]";

            return str;

        }

        if (0 <= opcode && opcode <= OP_PUSHDATA4) {

            if (vch.size() <= static_cast<std::vector<unsigned char>::size_type>(4)) {

                str += strprintf("%d", CScriptNum(vch, false).getint());

            } else {

                // the IsUnspendable check makes sure not to try to decode OP_RETURN data that may match the format of a signature

                if (fAttemptSighashDecode && !script.IsUnspendable()) {

                    std::string strSigHashDecode;

                    // goal: only attempt to decode a defined sighash type from data that looks like a signature within a scriptSig.

                    // this won't decode correctly formatted public keys in Pubkey or Multisig scripts due to

                    // the restrictions on the pubkey formats (see IsCompressedOrUncompressedPubKey) being incongruous with the

                    // checks in CheckSignatureEncoding.

                    if (CheckSignatureEncoding(vch, SCRIPT_VERIFY_STRICTENC, nullptr)) {

                        const unsigned char chSigHashType = vch.back();

                        const auto it = mapSigHashTypes.find(chSigHashType);

                        if (it != mapSigHashTypes.end()) {

                            strSigHashDecode = "[" + it->second + "]";

                            vch.pop_back(); // remove the sighash type byte. it will be replaced by the decode.

                        }

                    }

                    str += HexStr(vch) + strSigHashDecode;

                } else {

                    str += HexStr(vch);

                }

            }

        } else {

            str += GetOpName(opcode);

        }

    }

    return str;

}

std::string EncodeHexTx(const CTransaction& tx)

{

    DataStream ssTx;

    ssTx << TX_WITH_WITNESS(tx);

    return HexStr(ssTx);

}

void ScriptToUniv(const CScript& script, UniValue& out, bool include_hex, bool include_address, const SigningProvider* provider)

{

    CTxDestination address;

    out.pushKV("asm", ScriptToAsmStr(script));

    if (include_address) {

        out.pushKV("desc", InferDescriptor(script, provider ? *provider : DUMMY_SIGNING_PROVIDER)->ToString());

    }

    if (include_hex) {

        out.pushKV("hex", HexStr(script));

    }

    std::vector<std::vector<unsigned char>> solns;

    const TxoutType type{Solver(script, solns)};

    if (include_address && ExtractDestination(script, address) && type != TxoutType::PUBKEY) {

        out.pushKV("address", EncodeDestination(address));

    }

    out.pushKV("type", GetTxnOutputType(type));

}

void TxToUniv(const CTransaction& tx, const uint256& block_hash, UniValue& entry, bool include_hex, const CTxUndo* txundo, TxVerbosity verbosity, std::function<bool(const CTxOut&)> is_change_func)

{

    CHECK_NONFATAL(verbosity >= TxVerbosity::SHOW_DETAILS);

    entry.pushKV("txid", tx.GetHash().GetHex());

    entry.pushKV("hash", tx.GetWitnessHash().GetHex());

    entry.pushKV("version", tx.version);

    entry.pushKV("size", tx.ComputeTotalSize());

    entry.pushKV("vsize", (GetTransactionWeight(tx) + WITNESS_SCALE_FACTOR - 1) / WITNESS_SCALE_FACTOR);

    entry.pushKV("weight", GetTransactionWeight(tx));

    entry.pushKV("locktime", tx.nLockTime);

    UniValue vin{UniValue::VARR};

    vin.reserve(tx.vin.size());

    // If available, use Undo data to calculate the fee. Note that txundo == nullptr

    // for coinbase transactions and for transactions where undo data is unavailable.

    const bool have_undo = txundo != nullptr;

    CAmount amt_total_in = 0;

    CAmount amt_total_out = 0;

    for (unsigned int i = 0; i < tx.vin.size(); i++) {

        const CTxIn& txin = tx.vin[i];

        UniValue in(UniValue::VOBJ);

        if (tx.IsCoinBase()) {

            in.pushKV("coinbase", HexStr(txin.scriptSig));

        } else {

            in.pushKV("txid", txin.prevout.hash.GetHex());

            in.pushKV("vout", txin.prevout.n);

            UniValue o(UniValue::VOBJ);

            o.pushKV("asm", ScriptToAsmStr(txin.scriptSig, true));

            o.pushKV("hex", HexStr(txin.scriptSig));

            in.pushKV("scriptSig", std::move(o));

        }

        if (!tx.vin[i].scriptWitness.IsNull()) {

            UniValue txinwitness(UniValue::VARR);

            txinwitness.reserve(tx.vin[i].scriptWitness.stack.size());

            for (const auto& item : tx.vin[i].scriptWitness.stack) {

                txinwitness.push_back(HexStr(item));

            }

            in.pushKV("txinwitness", std::move(txinwitness));

        }

        if (have_undo) {

            const Coin& prev_coin = txundo->vprevout[i];

            const CTxOut& prev_txout = prev_coin.out;

            amt_total_in += prev_txout.nValue;

            if (verbosity == TxVerbosity::SHOW_DETAILS_AND_PREVOUT) {

                UniValue o_script_pub_key(UniValue::VOBJ);

                ScriptToUniv(prev_txout.scriptPubKey, /*out=*/o_script_pub_key, /*include_hex=*/true, /*include_address=*/true);

                UniValue p(UniValue::VOBJ);

                p.pushKV("generated", prev_coin.IsCoinBase());

                p.pushKV("height", prev_coin.nHeight);

                p.pushKV("value", ValueFromAmount(prev_txout.nValue));

                p.pushKV("scriptPubKey", std::move(o_script_pub_key));

                in.pushKV("prevout", std::move(p));

            }

        }

        in.pushKV("sequence", txin.nSequence);

        vin.push_back(std::move(in));

    }

    entry.pushKV("vin", std::move(vin));

    UniValue vout(UniValue::VARR);

    vout.reserve(tx.vout.size());

    for (unsigned int i = 0; i < tx.vout.size(); i++) {

        const CTxOut& txout = tx.vout[i];

        UniValue out(UniValue::VOBJ);

        out.pushKV("value", ValueFromAmount(txout.nValue));

        out.pushKV("n", i);

        UniValue o(UniValue::VOBJ);

        ScriptToUniv(txout.scriptPubKey, /*out=*/o, /*include_hex=*/true, /*include_address=*/true);

        out.pushKV("scriptPubKey", std::move(o));

        if (is_change_func && is_change_func(txout)) {

            out.pushKV("ischange", true);

        }

        vout.push_back(std::move(out));

        if (have_undo) {

            amt_total_out += txout.nValue;

        }

    }

    entry.pushKV("vout", std::move(vout));

    if (have_undo) {

        const CAmount fee = amt_total_in - amt_total_out;

        CHECK_NONFATAL(MoneyRange(fee));

        entry.pushKV("fee", ValueFromAmount(fee));

    }

    if (!block_hash.IsNull()) {

        entry.pushKV("blockhash", block_hash.GetHex());

    }

    if (include_hex) {

        entry.pushKV("hex", EncodeHexTx(tx)); // The hex-encoded transaction. Used the name "hex" to be consistent with the verbose output of "getrawtransaction".

    }

}